Traditionally, horseshoes are heated in a transportable gas forge. Because the shoeing takes place on site, the farrier is obliged to transport all his equipment, namely:                forge, anvil and tools,        range of different sizes of shoe,        miscellaneous portable electrical equipment,        two gas bottles (the need to have available a recharge).        
The transportation of gas bottles in a vehicle presents certain risks that are not covered by insurance unless equipped with a strong sealed box, of given dimensions and thicknesses, fixed outside the vehicle. Such compliance with safety standards proves unsuitable for the majority of users, who have lightweight vehicles of the van type. All the more so since it represents a prohibitive cost. Thus, in reality, only a very small minority of farriers work in complete conformity.
Gas forges have other major drawbacks that are added to already difficult working conditions. Such as the noise generated by the burners, which stress some horses to the point of preventing any work.
When it is necessary to take the shoes out of the fire, extreme heat causes burns to the hands and arms, the use of gloves not being very compatible with the activity. The flame of the gas forge is oxidising. At high temperature, it rapidly produces a great deal of scale (iron oxide vapours). Prolonged exposure to these gaseous emissions causes respiratory and cardio-vascular complications in some people.
From the economic point of view, the energy balance of a gas forge in its current design may be considered disastrous. This is because the very operating principle requires the continuous discharge of burnt gases, and therefore heat. Thus, out of all the energy consumed, the part actually absorbed by the loads scarcely exceeds 10%.